﻿using System;
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Windows.Forms;
using NAudio.Wave;
using System.Diagnostics;

namespace WindowsFormsApplication3
{
    /// <summary>
    /// Control for viewing waveforms
    /// </summary>
    public class BaseWaveView : System.Windows.Forms.UserControl
    {
        /// <summary> 
        /// Required designer variable.
        /// </summary>
        protected System.ComponentModel.Container components = null;
        protected WaveStream waveStream = null;
        protected int samplesPerPixel = 128;
        protected long startPosition = 0;
        protected int bytesPerSample = 0;
        /// <summary>
        /// Creates a new BaseWaveView control
        /// </summary>
        public BaseWaveView()
        {
            // This call is required by the Windows.Forms Form Designer.
            InitializeComponent();
            this.DoubleBuffered = true;

        }

        /// <summary>
        /// sets the associated wavestream
        /// </summary>
        public WaveStream WaveStream
        {
            get
            {
                return waveStream;
            }
            set
            {
                waveStream = value;
                if (waveStream != null)
                {
                    bytesPerSample = (waveStream.WaveFormat.BitsPerSample / 8) * waveStream.WaveFormat.Channels;
                }
                this.Invalidate();
            }
        }

        /// <summary>
        /// The zoom level, in samples per pixel
        /// </summary>
        public int SamplesPerPixel
        {
            get
            {
                return samplesPerPixel;
            }
            set
            {
                samplesPerPixel = value;
                this.Invalidate();
            }
        }

        /// <summary>
        /// Start position (currently in bytes)
        /// </summary>
        public long StartPosition
        {
            get
            {
                return startPosition;
            }
            set
            {
                startPosition = value;
            }
        }

        /// <summary> 
        /// Clean up any resources being used.
        /// </summary>
        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                if (components != null)
                {
                    components.Dispose();
                }
            }
            base.Dispose(disposing);
        }
        public long Samples
        {
            get
            {
                return waveStream == null ? 0 : waveStream.Length / bytesPerSample;

            }
        }

        /// <summary>
        /// <see cref="Control.OnPaint"/>
        /// </summary>
        protected override void OnPaint(PaintEventArgs e)
        {
            try
            {
                if (waveStream != null)
                {
                    waveStream.Position = 0;
                    int bytesRead;
                    byte[] waveData = new byte[samplesPerPixel * bytesPerSample];
                    waveStream.Position = startPosition + (e.ClipRectangle.Left * bytesPerSample * samplesPerPixel);

                    for (float x = e.ClipRectangle.X; x < e.ClipRectangle.Right; x += 1)
                    {
                        short low = 0;
                        short high = 0;
                        bytesRead = waveStream.Read(waveData, 0, samplesPerPixel * bytesPerSample);
                        if (bytesRead == 0)
                            break;
                        for (int n = 0; n < bytesRead; n += 2)
                        {
                            short sample = BitConverter.ToInt16(waveData, n);
                            if (sample < low) low = sample;
                            if (sample > high) high = sample;
                        }
                        float lowPercent = ((((float)low) - short.MinValue) / ushort.MaxValue);
                        float highPercent = ((((float)high) - short.MinValue) / ushort.MaxValue);
                        e.Graphics.DrawLine(Pens.Black, x, this.Height * lowPercent, x, this.Height * highPercent);
                    }
                }
            }
            catch (Exception exc)
            {
                Debug.WriteLine(exc.Message);
            }

            base.OnPaint(e);
        }


        #region Component Designer generated code
        /// <summary> 
        /// Required method for Designer support - do not modify 
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.SuspendLayout();
            // 
            // BaseWaveView
            // 
            this.Name = "BaseWaveView";
            this.Load += new System.EventHandler(this.BaseWaveView_Load);
            this.ResumeLayout(false);

        }
        #endregion

        private void BaseWaveView_Load(object sender, EventArgs e)
        {

        }
    }
}
